Electric generator.



J. F. KELLY.

ELETRIC GENERATOR.

APPLICATION FILED @20.20.1910.

1,088,781', Patented Mar. 3, 1914 als cuit of lowest `voli( JHN F. KELLY, 0F IXTTSFIELC, MASSACHUSETTS.

ELECTRIC GENERTCR,

Application filed December 2G, tSG.

Specification of Letters Patent.

lfntcnted Mar, 3, 1914.

sei-:asi uo. 593,404.

To all whom 'it may concern Be it known that l, JOHN F, KELLY, a citizen of the United States, residing at Pittsfield, county of Berkshire, and State of Massachusetts, have invented certain new and useful Improvements in Electric Gern erators, fully described and represented in the following specilication and the accom partying drawings, forming a. part the same.

This inventionrelates to dynamo electric generators for supplying a plurality ot cir cuits at different voltages. i The ordinary compound wound generator having a single brush or terminal on one side of 'the neutral plane of the armature, and a single series coil connected therewith may be used for supplying a plurality ot circuits at different voltages by providing a plurality ,of difierently disposed brushes on the othe side the armature. All the working circuits will then pass thriuigh this coil and the one brush to which it is connected, and this one Coil may be made to give goed service in preventing too (frei a dein-essieu in the Voltage in any or such circuits there is no comparatively lange ditlerence in voltage between the circu of highest a. d the cirg'c. The di in voltage is obtained in such wholly by displacing the brushes on one side only ot the n'iachine7 and to obtain a wide difference ol voltage in this way u'ouiif 'e sult in placing one more of the brushes where'commutation would be had or aven disastrous. This is avoided in accordance with the present invention by providing two or more brushes on each side of the neutral plane 01"' the armature, and a seperate series coil for each of the brushes on either side ot the machine if the same number of brushes i.: provided on both sides, or a `series coil for each of the brushes on the side having the lesser number ot' brushes if there is a dilier ent number of brushes-on the two sides ot "the machine; the object of the invention being to provide a. compound Wound dynamo electric generator which may be used tor supplying a plurality of circuits with cur rents ot' substantially ditl'erent voltages, with proper regulation or control oi the voltage of cach circuit and without havingl the current. drawn through any one or more circuits re-act on the voltage of the other circuit or circuits.

,lt has been sought to use a compound wound generator for supplying the operating magnets of an electrically operated piano player with current of di'il'ereut. voltages for producing the desired variations in strength of action and loudness ot' tones produced, but it has been found that such use is practicallylimited to two circuits of such difference in voltage as is necessary to produce the desired dill'erence in loudiiess of tones. 'lhe present invention has been made primarily with the object of providing a generator for such use from which three or more circuits at substantially different voltug, s may be supplied. It will be under` stood, however, that the invention not liniitcri in its application to generators intended 'or such use, or to generators for supplying low voltage currents such as are adapted for this use.v this application of the invention being; mentioned merely for the purpose of giving an example of conditions to be niet and results which -an be obtained 'by the present invention which could not be niet or obtained by 'the use of thc ordinary uuid wound. dynamo.

"Elliot-nv: p...

mie accompanying, magiam i ustlatcs an application the invention to a generator tor supply! ,fr up te .tour circuits at diti'ei" v to .aid diagram, the armature l the closed circuit type and will. #eviden with three or more brushes or pals. As shown, tour such brushes' or s areprovidet'l, marked l, 2, 3, and y e brushes l and 2 being,` of one polarity, say positive, and the brushes 3 and 4; ofthe opposite or negative polarity, that is, the brushes l and 3 are in the neutral )lane ud the brushes 2 and 4 on opposite sides of thc neutral plane of the armature.

The shunt ield coil B is shown as connected between the brushes 1 and 3, and two series held coils C and C are provided, one in each of the vlines leading from the brushes 23 and et respectively. Four circuits :it voltages (littering according to the position of the brushes are thus provided for, that is, a circuit conmuzting the brushes 1 and 3, one connecting the brushes l and 4, one connecting the brushes 2 and 3, and a' fourth circuit. connecting the brushes l and Il. Two or" the brushes. as l and 3, are preferably dianietrically opposite points of greatest u) WE l voltage ggsnera'or pmi lis bis a' lizwi' alle cir/mii; connecting the brushes and 3, 2G l2 vol?k 'for the Cilicuifz Connecting lle bius' and 3, 10 volts :for the circuit conmeti. 'brushes :md 8 volts; for

comifscti 'Je classi.

simil; regulation .sii ii.. the blush l Then 'w @fea an el@ciro-moivedfrce of l with priictloal accumula gli.

ug lie bruslms 2 and -ved @lift there. is "illus Series coil if and in such case the brush i3 and under normal 'afLi-iafiens in load on :my Si; me or mor@ circuits.

While the constiuczi i "imi/Gd in (alle diagram pifovdcs .c ...frulmifm wih this@ o? mur cil's'uis taking L .mi cleien voltages from the @wel provision 01' glia iw@ Series m" i soils is useful where clase regulation im only wo circuits of diffrent voltages is deixfcd, 'iight lic omitte unless the difference in voltage is Gr; comparatively large, in which went lle bi'usl'l 2 bfest etained.

bvimisly the number of ciifui'ts i iii 'ferent voltages supplied by the Y valor might be increased Without deimrting from f5.3 the invention by increasing the number dili'erently disposed Liuslies o1: terminals und the. number of Series lielcl coils.

What claimed is:

.ln :i multi-circuit compound-wound (ly- 70 Haino electric .machine designed to supply iui'lpeiideut external circuits with clureufswhose voltages are (liiei'eiit and constant, in cmiibinution with single field mug1ietmeml' and a closed circuit armature, 0l' a plu-A 'i5 un y of positive and negative biilslies, :L shun @Gil Connected 'ai pail' 0i" Ubi'uslica, copelatng series coils equal in nunzlei: to lille b ushes of one poluiiiy and. having mi@ 'i'uirml of man Soriana coil coimctecl l'espeg@ y ik() aid brushes of that polarity und other terminales counseled i' im@ folu'iing piu-b oi the cumpouild the field l luacls :ilslo fom und w bruid, in h@ iwf-smic@ olif' uw Suiwl'iln;

mi; L Eismann, 

